[Effects of Different Concentrations of Glucose on the Osteogenic Differentiation of Orofacial Bone Mesenchymal Stem Cells].

Objectives: To determine the effects of different concentrations of glucose on the proliferation and osteogenic differentiation of orofacial bonemesenchymal stem cells (OFMSCs).

Methods: OFMSCs were primarily cultured and identified to undergo osteogenic/adipogenic/chondrogenic differentiation. The cells were exposed to osteogenic medium containing different levels of glucose: 5.5,11,16.5,25,44 mmol/L. The cell activity and proliferation index were measured using a cell counting kit (CCK)-8 and flow cytometry. The alkaline phosphatase (ALP) activity of the cells was measured at the 4 and 7 day. Alizarin red staining was carried out at the 21 day. RT-PCR detecting osteogenesis-related gene and Osterix mRNA expression was performed at the 4, 7, 14 and 21 day.

Results: Osteogenesis induced calcium nodes was observed with Alizarin red staining at the 21 day. Adipogenic induced red lipid droplets was observed with Oil Red O staining at the 14 day. Chondrogenic induced blue cytoplasm was observed with Alcian blue staining at the 14 day. With 5.5 to 25 mmol/L glucose,OFMSCs proliferation was promoted.But when the concentration of glucose continued to increase (from 25 to 44 mmol/L),OFMSCs proliferation significantly reduced.The ALP activity decreased with glucose in a concentration-dependent manner ( <0.05). Osteogenesis induced Alizarin red staining and mineralization showed at the 21 day. The calcium nodes and mineralization quantity decreased with glucose in a concentration-dependent manner ( <0.05).The cells exposed to 5.5 mmol/L glucose had a higher level of expression of and Osterix mRNA than the others (<0.05).The experssion of and Osterix mRNA in all groups showed a trend of rising first, followed by an obvious down regulation.

Conclusions: With certain limits,OFMSC proliferation is promoted by glucose. Osteogenic differentiation is inhibited by glucose in a concentration-dependent manner.